1. Field of the Invention
The present invention relates to a hand pump, and more particularly, to a hydraulic double-acting hand pump in which a pair of pistons installed in high and low pressure side fluid supply grooves alternatively ascend and descend, and fluids in the high and low pressure side fluid supply grooves are discharged to the outside of a body.
2. Discussion of Related Art
Generally, a pump is a device which transfers fluids through a pipe using a pressure effect or forcibly transfers fluids inside a low pressure container into a high pressure container through a pipe.
Here, in addition to water, the pump is also used in transferring special fluids including oil, chemical, or pulp, viscose, etc.
Here, the pump includes a discharge valve and a suction valve therein, and due to a reciprocating motion of the piston, the discharge valve and the suction valve are alternatively opened and closed to discharge and suction liquid.
Patent document KR10-0199658 B1 shows a conventional reciprocating electronic pump. Referring to the Patent document 1, the conventional reciprocating electronic pump includes a cylinder in a hollow shape, a piston which is installed in the cylinder and laterally moves in a reciprocating manner, a solenoid which is installed to surround an outer circumferential surface of the cylinder and provides a magnetic force to the piston, suction pipes which supply fluids to the cylinder through both ends of the cylinder, and a discharge pipe which discharges the fluids in the cylinder to the outside of the cylinder.
Here, when the piston is moved toward the left in the cylinder by the magnetic force of the solenoid, fluids remaining in space on the left in the cylinder are discharged to the outside through the discharge pipe formed on the left thereof, and at this point, fluids are supplied through the suction pipe formed on the right thereof to be supplied to space on the right in the cylinder.
Next, when the piston is moved toward the right in the cylinder by the same method as described above, the fluids remaining in space on the right in the cylinder are pushed by the piston and discharged to the outside of the cylinder through the discharge pipe formed on the right.
At this point, the fluids are supplied to the space on the left in the cylinder through the suction pipe formed on the left.
That is, the piston is laterally moved in a reciprocating manner in the cylinder by the solenoid to push the fluids inside the cylinder to the outside and at this point, forcibly suctions fluids into the cylinder.
However, in a patent document such as the above Patent document 1, an external influence on the magnetic force between the solenoid and the piston causes the piston not to properly perform reciprocating motions, speed of the reciprocating motion is changed according to the variation of the pressures of the suction pipe and the discharge pipe, an operation of the piston stops when the pressure in the cylinder is raised higher than the magnetic force of the solenoid, and thus there is a problem in that the reliability of a product is degraded because the fluid suction and discharging are not performed due to the inoperability of the piston.